better use 'If Empty(cVariable)' code to check if a variable is empty.

Using '=' is a mistake as the logic of it is to stop checking after reaching end of 'right side' text.
So, 'abcd' = 'ab' is true
but 'abcd' == 'ab' is false
So 'abcd' = '' will be always true
but 'abcd' == '' will be false.